This invention relates generally to methods and apparatus for measuring navigation parameters of a locomotive, and more specifically to methods of determining movement and direction of a track-bound transportation apparatus using GPS satellites.
Modem algorithms for train navigation incorporate very sensitive turn rate gyroscopes (gyros) that permit detection of low speed through high number turnouts such as a #20 equilateral turnout. These gyroscopes are quite expensive, and suffer from coning problems due to superelevation. In addition, measurement drift accumulates over time. This drift must be corrected periodically by reference to data in a track data base. It would therefore be desirable to replace gyroscopes (gyros) in such applications altogether or to provide an alternate system for determining heading accurately for low speed and high speed turnouts. Where trains move over a curving track, the rails wear down due to friction between the wheels of the train and the rails. As used herein, a curve is represented by any change in path direction. Therefore, curving means that a path direction is changing. One solution to this problem is to provide lubricant to the rails or to the wheels when a train is moving. However, this solution is wasteful of lubricant. It would therefore be desirable to provide a method and apparatus to more efficiently reduce rail wear on curving tracks by determining when a train is on a curve and by applying lubricant.